Tetramethylolcyclohexanol treatment to trevent popping and fading of transparencies and fading of color prints



Unite States Patent TETRAMETHYLOLCYCLOHEXANOL TREAT- MENT TO PREVENT POPPING AND FAD- PING or TRANSPARENCIES AND FADING "or COLOR PRINTS Norman D. Clarke, Roy A. Jelfreys, and David G. Saunders, Harrow, England, assignors to Eastman Kodak Company, Rochester, NY, a corporation of New Jersey *No Drawing. Filed Jan. 26, 1959, Ser. No. 788,765

7 3 Claims. (CI. 96-55) This invention concerns the treatment of colored photographs, more particularly to a final rinse bath to stabilize the dyes present in the image layers.

Many of the colored photographic elements which are in use are subject to fading and the like due to light and heat during optical projection, and extreme humidity condition. Inasmuch as the colors alter unevenly, the color balance can be changed so that the color portrayal is no longer accurate. Often a deterioration of the colored image takes place resulting in the yellowing or browning of the colored photograph when stored in a heated atmosphere. In .some instances, staining or browning of the white areas occurs due to the deterioration of residual unused couplers left in the light sensitive areas after processing. This coupler deterioration arises due to the action of light and also due to the action of heat and high humidity. Another result of color instability is loss of the yellow or other color.

A problem peculiar to transparent photographic elements is that of avoiding popping of colored photographic transparencies during optical projection. Popping is a characteristic of most transparencies which occurs when the transparency is placed in the slide changer through which the light is transmitted. Due to the heat, the transparency buckles with a resulting change in focus which necessitates refocusing. Many solutions have been suggested for the problem, including lacquering the transparency, redesigning the projector to provide a cooled light, and the like. However, it has been desirable to find a simple treatment for the transparencies which will prevent them from popping without deleteriously effecting the transparency itself.

We have found a simple method of treating colour photographs after they have been processed which results in remarkable color stability even when subjected to ad verse conditions.

One object of this invention is to provide a method of stabilizing the colors in colored photographs. Another object is to provide stabilized colored transparencies which can be projected optically without popping. A further object is to provide a simple method of after-treatment for colored photographic elements which will stabilize the colors against deterioration or alteration.

The above objects are obtained by treatment of the photographic elements with an aqueous solution containing 520% by weight of a tetramethylol cyclic alcohol or ketone having 5-8 carbon atoms in the ring. The photographic element whether a print, a transparency or a negative is dipped in the bath of the cyclic alcohol or ketone for 1-10 minutes, although this period is not critical. Surplus liquid can be removed with a squeegee, rapid water wash or other means. The photographic element may then be dried at room temperature or more rapidly in an oven.

Patented May 9, 1961 n=13 R=CO or CHOH W, X, Y, Z=methylol groups A polymethylene glycol having from 4 to 8 carbon 5 atoms such as 2-methylpentane-2,4-diol may be added as a plasticizer in the treatment bath at a concentration of about 2-3% by weight. Other polymet'hylene glycols which may be used include hexyleneglycol, hexamethy1ene-l,6-diol, 3-methylpentane-1,5-diol, tetrarnethylene-l,4-diol, Z-ethoxyethanol and the like.

The following examples illustrate our invention but are not intended to limit it in any way.

Example 1 Fully processed colored transparencies of the type described in 11.8. Patent 2,304,939, containing three layers of light-sensitive emulsion, each layer being sensitive to a particular color, such as the blue-sensitive silver halide layer, green-sensitive silver halide layer, and red-sensitive silver halide layer were dipped in a solution of 8% tetramethylol cyclohexanol and 2% 2-methylpentaue2,4-diol for 2 minutes, squeegeed and dried at room temperature. These transparencies did not pop in a Kodaslide projector with a 250-watt lamp during 3 minutes. An untreated slide popped within 15 seconds.

Slides were also treated with 5, 10, 15 and 20% solutions of tetramethylolcyclohexanol, and with mixtures of 5%+2%, 10%+2%, 15%+2% and 10%+2.5% con centrations of tetramethylolcyclohexanol and 2-rnethylpentane-2,4-diol. None of the slides treated popped during 1 /2 minutes.

Example 2 Color transparencies of the type described in Example 1 were fully processed and washed. These transparencies were immersed in an aqueous solution of tetramethylolcyclohexanol for 10 minutes, squeegeed and dried. Together with a water-washed slide they were exposed to light from a SOD-watt tungsten filament lamp at a distance of 8.5 inches for hours in a Fadorneter, and at the same time cooled by a current of air blown through the Fadometer. The following table gives the approximate percentage loss of density (from an original density of 1.0) for the yellow and magenta images. The cyan dye Example Color prints prepared according to US. Patent 2,272,191, were processed, washed, and immersed for 10 minutes in an aqueous solution of tetramethylolcyclohexanol. The prints were squeegeed and dried. To-

Percent Density Loss In creased From 1.0 Stain (Blue reflection Prnit Treatment Density) Cyan Magenta Yellow Control 7 33 g 45 0.11 to 0.25 Water wash 7 46 50 0. 11 to O. 25 10% tetramethylol clohexanol 2 14 0. 12 to 0. 10

Example 4 Color transparencies of the type described in Example 1 are immersed in a 7.5% solution of 2:2:52S-tetramethylolcyclopentanone in water for 10 minutes, then removed from the solution, surplus liquid squeegeed oil, and dried.

Example 5 Color transparencies of the type described in Example 1 are immersed in a 7.5% solution of 2:2:6z6-tetramethylolcyclohexanone in water for minutes, then removed from the solution, surplus liquid squeegeed off, and dried.

Example 6 Color prints of the type of Example 3 are immersed in a 10% solution of 2:2:5:S-tetramethylolcyclopentanone in water for 10 minutes, then removed from the solution, surplus squeegeed oh, and dried.

Example 7 Color prints of the type of Example 3 are immersed in a 10% solution of 2:2:6:6rtetramethylolcyclohexanone in water for 10 minutes, then removed from the solution, surplus liquid squeegeed off, and dried.

Example 8 Color transparencies of the type described in Example 1 are immersed in an 8% solution of 2:2:6z6-tetramethylolcyclohexanol and 2% of 2-ethoxyethanol in water for 10 minutes, then removed from the solution, surplus liquid squeegeed off, and dried.

Example 9 Color transparencies of the type described in Example l are immersed in an 8% solution of 2:216:6-tetramethylolcyclohexanol and 2% tetramethylene-1z4-diol in water for 10 minutes, then removed from. the solution, surplus liquid squeegeed off, and dried.

Example 10 Color transparencies of the type described in Example 1 are immersed in a 10% solution of a mixture of 3- methyland 4-methyl-2: 2: 6 6-tetramethylolcyclohexanol in water for 10 minutes, then removed from the solution, surplus liquid squeegeed 011?, and dried.

Example 11 Color transparencies of the type described in Example 1 are immersed in an aqueous solution of 8% 2:2:6z6-

4 tetramethylolcyclohexanone and 2% hexyleneglycol in water for 10 minutes, then removed from the solution, surplus'liquid squeegeed OE, and dried.

Photographic colored elements which are operative in our invention include those-illustrated in the examples as well as those disclosed in U.S. Patent 2,296,306. They also include color positive print material coated on paper in which the color formers are present in the emulsion or are obtained using a selective second exposure'followed by development by developing solutions containing color formers and color developing agents. Other color elements include color reversible film, color negative film, and color reversible white printing mate: rial coated on an opaque base. M v 4 An example .of. a developing. process for colored photographic elements known as the E2 Process is disclosed in copending U.S. patent application. Serial No. 699,478, filed November 29, 1957,1'in the name of Henn et a1. Following this color developing process, the colored photographs are rinsed in a tetramethylolcyclohexanol bath.

We claim:

1. In a process of producing gelatino colored photographic images in a multicolor photographic element by exposing a silver halide photographic emulsion, color developing, bleaching, fixing and washing the photographic element, the improvement which comprises sta bilizing the dyes and preventing the discoloration of the photographic image and preventing popping, comprising rinsing the processed photographic image with an aqueous solution containing 520% of tetramethylolcyclohexanol for l-l0 minutes. 7 g

2. A method of treating gelatino fully processed colored photographic transparencies comprising wetting the gelatino image carrying layer for 1-l0 minutes with an aqueous solution of 520% of a cyclic compound having the general formula:

H don. Y' in which n is 0-2, R is selected from the class consist ing of CO and COH, Y is methylol, and 2-3% by weight of a polymethylene glycol having 4-8 carbon atoms.

References Cited in the file of this patent UNITED STATES PATENTS 2,725,305 Allen et al. Nov. 29, 1955 2,870,013 Jefireys Jan. 20, 1959 2,895,827

Callear et a1 July 21, 1959 

2. A METHOD OF TREATING GELATINO FULLY PROCESSED COLORED PHOTOGRAPHIC TRANSPARENCIES COMPRISING WETTING THE GELATINO IMAGE CARRYING LAYER FOR 1-10 MINUTES WITH AN AQUEOUS SOLUTION OF 5-20% OF A CYCLIC COMPOUND HAVING THE GENERAL FORMULA: 